1. Field of Invention
The invention relates to an image display system and, in particular, to an image display system with transversely aligned liquid crystals.
2. Related Art
The liquid crystal display (LCD) apparatus is a flat display system. The LCD apparatuses may be classified into a twisted nematic (TN) type, a multi-domain vertical alignment (MVA) type, an in-plane switching (IPS) type and a fringe-field switching (FFS) type according to the arrangements of the liquid crystals. The MVA type, the IPS type and the FFS type are frequently seen in the field of the wide viewing angle display technology.
The typical IPS or FFS type LCD apparatus includes top and bottom substrates disposed opposite to each other, and a liquid crystal (LC) layer interposed between the two substrates. Pixel electrodes and common electrodes are simultaneously disposed on the bottom substrate so that a transversal electric field is generated in the LC layer to control the liquid crystals to rotate.
On the other hand, the LCD apparatuses may also be classified into a transmissive type, a transflective type and a reflective type according to the form of the light source. The transflective LCD apparatus has a backlight module and an external light reflecting structure, so it can be watched by a user in the environment without external light as well as the environment with the sunlight.
The viewing angle of the transflective LCD apparatus may be increased with the combination of the alignment method of the liquid crystals in the IPS type or the FFS type LCD apparatus. More specifically, the alignment method of the liquid crystals in the FFS type LCD apparatus can achieve the advantages of the high transmission rate and the low color shift. However, such a small-sized LCD apparatus is more sensitive to the cell gap between the substrates and the temperature variation in the transmissive mode, and also has the problem of the deteriorated viewing angle. Especially, the image contrast is seriously lowered when the slight alternate variation of the substrate occurs.
Therefore, it is an important subject to provide an image display system for reducing the alternate variation of the substrate so as to keep the image quality.